Integration of Simulations and Experiments for Modeling Superalloy Grain Growth

نویسندگان

  • Eric Payton
  • Gang Wang
  • Ning Ma
  • Yunzhi Wang
  • Michael Mills
  • Deborah Whitis
  • David Mourer
  • Dan Wei
چکیده

Grain size is an important parameter controlling the mechanical behavior and useful life of turbine disks. During heat treatment above the gamma prime (γ′) solvus the grain size increases dramatically as the γ′ particles dissolve. The grain size then stagnates as the volume fraction of the γ′ phase approaches zero. In general, the grain size at stagnation cannot be described by classic Zener pinning theory because of its strong dependence on the strain rate and thermal exposure during thermomechanical processing. The grain size distribution, twin boundary fraction, γ′ size distribution and volume fraction, carbide size distribution and volume fraction, γ′ dissolution rates, and carbide coarsening rates have been measured in two powder metallurgical disk superalloys. Stored energy and boundary properties after deformation have been assessed. The experimental results have been used as input parameters for a physics-based model of grain growth in a field of two populations of particles, one coarsening and one dissolving. Phase field models have been used to support and clarify interpretations of experimental results and to validate the appropriate functional forms for precipitate coarsening and dissolution. Comparison of experimental and modeling results have suggested avenues for further experimental investigations and vice versa. This established feedback loop between experimentation and simulation has enabled focused experimentation, increasing the accuracy and general applicability of the model.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Simulation of Creep Crack Growth of a Directionally-solidified Ni-base Superalloy

Creep lifetime of turbine blade material subjected to sustained centrifugal forces at elevated temperatures is limited by accumulated inelastic deformation and creep crack growth (CCG). Creep resistance exhibited in conventionally cast polycrystalline (PC) Ni-base superalloy components has been enhanced via solidification techniques. Directional solidification (DS) results in large grain sizes ...

متن کامل

Evolution of the Annealing Twin Density during -Supersolvus Grain Growth in the Nickel-Based Superalloy InconelTM 718

Grain growth experiments were performed on InconelTM 718 to investigate the possible correlation of the annealing twin density with grain size and with annealing temperature. Those experiments were conducted at different temperatures in the supersolvus domain and under such conditions that only capillarity forces were involved in the grain boundary migration process. In the investigated range, ...

متن کامل

Finite Element Modeling of Strain Rate and Grain Size Dependency in Nanocrystalline Materials

Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...

متن کامل

Impact of Oil, Crises and Economic Integration on Growth:

While energy especially oil, crises and economic integration have been playing an important role indevelopment and growth in East West Asia economies and their intertwining relations, only limitedquantitative research on their impact has been carried out and reported for improved debate andcredible policy use. This paper uses an econometric modeling innovation with features superior toexisting ...

متن کامل

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were estab...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008